Physics of Fluids,
Год журнала:
2022,
Номер
34(10)
Опубликована: Сен. 10, 2022
To
investigate
the
unsteady
evolution
characteristics
and
mechanism
of
cavitation
at
tongue
its
influence
on
flow
field
in
a
centrifugal
pump,
numerical
calculations
were
performed
to
research
occurrence
development
under
large
rate
(1.3Qd)
conditions.
The
calculation
results
verified
by
experiments.
proper
orthogonal
decomposition
(POD)
method
was
used
decompose
reconstruct
pump.
relationship
between
typical
frequency
pressure
pulsation
mainstream
structure
established.
POD
could
accurately
extract
coherent
caused
capture
unstable
produced
vortex
shedding.
Under
different
available
net
positive
suction
head
conditions,
first
mode
structural
original
field,
with
low-frequency
single-frequency
components.
second,
third,
fourth
modes
main
oscillation
showed
high
multiple
frequencies.
High-order
complex
change
large-scale
induced
cavitation.
Tip
leakage
flow
is
one
of
the
significant
factors
influencing
internal
stability
mixed-flow
pumps,
and
in
severe
cases,
it
can
lead
to
channel
blockage
energy
loss.
In
order
gain
a
deeper
understanding
dissipation
mechanism
induced
by
tip
vortex
cavitation,
this
study
based
on
Wray–Agarwal
(WA)
turbulence
model
homogeneous
model,
investigating
cavitation
characteristics
pumps.
Additionally,
entropy
production
theory
employed
evaluate
losses
within
pump
analyze
components
loss
impeller
guide
vanes.
The
research
results
reveal
that
with
increasing
intensity,
low-pressure
region
at
leading
edge
blade
extends
toward
trailing
edge,
static
pressure
distribution
blade's
side.
Leakage
spatial
vortices
move
closer
suction
side
intensity.
Cavitation
primarily
affects
region,
turbulent
being
main
source
High
zones
are
concentrated
blade,
correlating
recirculation
trailing-edge
vortices.
This
provides
theoretical
insights
practical
implications
for
enhancing
performance
offering
valuable
guidance
design
operation.
